1. Biology Ecology Unit

2. Energy in Ecosystems  Consumers: get their energy by eating other living or once- living resources such as plants or animals  Also called heterotrophs  Producers: get their energy from nonliving resources, meaning they make their own food.  Also called autotrophs

3. Energy in Ecosystems  Some organisms make food without sunlight   Chemosynthetic Organisms  Even animals that eat only meat rely on producers  Grey Wolf: Eats Elk and Moose, but  Elk and Moose eat grasses and shrubs

4. Food Chains and Food Webs  Types of Consumers:  Herbivores: only eat plants  Carnivores: only eat animals  Omnivores: eat both plants and animals  Detritivore: an organism that eats “detritus”, or dead organic matter.  Decomposers: detritivores that break down organic matter into simpler compounds  Specialists: a consumer that primarily eats on specific organism or feeds on a very small number of organisms  Generalists: consumers that have a varying diet

5. Food Chains and Food Webs  Trophic Levels:  Producers: plants  Primary Consumers: herbivores  Secondary Consumers: carnivores that eat herbivores  Tertiary Consumers: carnivores that eat secondary consumers  Omnivores, such as humans, may be listed at different levels in different food chains

6. Food Chains and Food Webs  Food Chain: A sequence that links species by their feeding relationships.

7. Food Webs and Food Chains  Food Web: a model that shows the complex network of feeding relationships and the flow of energy within an ecosystem  An organism may have multiple feeding relationships within a food web

8. Cycling of Matter  Hydrologic Cycle/Water Cycle: the circular pathway of water on Earth  Atmosphere  Surface  Below the Ground  Back into the Atmosphere

9. Biogeochemical Cycles  Biogeochemical Cycle: the movement of a particular chemical through the biological and geological, or living and nonliving, parts of an ecosystem.  1. Oxygen Cycle  2. Carbon Cycle  3. Nitrogen Cycle  4. Phosphorus Cycle

10. Biogeochemical Cycles  The Oxygen Cycle  -Plants, animals, and most other organisms use oxygen for cell respiration  -Plants release oxygen as a waste product

11. Biogeochemical Cycles  The Carbon Cycle  -Carbon continually flows from the environment to living organisms and back again in the carbon cycle  -Sources of Carbon:  CO2 in the atmosphere  Bicarbonate (HCO3) dissolved in water  Fossil Fuels  Carbonate Rocks  Dead organic matter

12. Biogeochemical Cycles  The Nitrogen Cycle  -78% of Earth’s atmosphere is made up of Nitrogen  Much of the nitrogen cycle occurs underground –Some bacteria convert gaseous nitrogen into ammonia through a process called nitrogen fixation. –Some nitrogen-fixing bacteria live in nodules on the roots of plants; others live freely in the soil.

13. Biogeochemical Cycles  Nitrogen Cycle Continued…  Ammonia released into the soil is transformed into ammonium.  Nitrifying bacteria change the ammonium into nitrate.  Nitrogen moves through the food web and returns to the soil during decomposition.

14. Biogeochemical Cycles  Phosphorus Cycle  The phosphorus cycle takes place at and below ground level.  Phosphate is released by the weathering of rocks.  Phosphorus moves through the food web and returns to the soil during decomposition.  Phosphorus leaches into groundwater from the soil and is locked in sediments.  Both mining and agriculture add phosphorus into the environment.

15. Pyramid Models  Pyramids model the distribution of energy and matter in an ecosystem.  Three types of pyramids:  1. Energy Pyramid  2. Biomass Pyramid  3. A Pyramid of Numbers

16. 1. Energy Pyramid  Energy Pyramids compare energy used by producers, primary consumers, and other trophic levels.  Between each tier, up to 90% of the energy is lost as heat into the atmosphere.  Shows the important role producers play in an ecosystem.

17. 2. Biomass Pyramid  Biomass pyramids compare the biomass of different trophic levels within an ecosystem.  Biomass: a measure of the total dry mass of organisms in a given area. (g/m2)  Shows the important role producers play in an ecosystem.

18. 3. A Pyramid of Numbers  A pyramid of numbers shows the number of individual organisms at each trophic level in an ecosystem  Shows the important role producers play in an ecosystem.

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